Oil treatment process and apparatus therefor



H. C. KIRK OIL TREATMENT PROCESS AND APPARATUS THEREFOR March 14, 1933.

Filed Dec. 8, 1927 2 Sheets-Sheet 1 g Fig.2.

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Patented Mar. 14, 1933 ENRY KIRK, F BALTIMORE, MARYLAND; COLONIAL TEUSlT COMPANY EXECUIORS hddld'lz.

0F SAID HENRY C. KIRK, DECEASED OIL TREATMENT PROCESS AND APPARATUS THEREFOR Application filed December 8, 1927. Serial .No. 238,648.

' tremendous element of expense in labor involved in the removal of the accumulated carbon, winch is hard and graplntic or cokelike. The suggestions in the prior'art for elimination of carbon trouble are legion,

but heretofore no successful solution of the problem has been found.

One of the primary objects of this invention is the carryingout of the oxygenation heat trea tnient of oils and related substances wherein no hard. coke-likecarbon is formed or deposited, any carbon which is formed during the process being soft or mud-like and readily removable with the tar drawn off in the tar line.

lllany other objects and advantages will appear from the more detailed description set forth below, it being understood however that this more detailed description is given by way of illustration, and not as limiting, since various changes may be made in the method and apparatus by those skilled in the art, without departing from the spirit and scope of this invention.

In connection with this more detailed illustrative description, consideration should be taken of the accompanying drawings wherein there is shown, in

Figure 1, an elevation partly in section of a treatment still embodying the invention; in

Figure 2, a detail partly in section of the 'air and oil inlet nozzles; and in Figure 3, a detail partly in section of one cf the ends of the air-oil inlet nozzles Figure 4, an elevation partly in section of a treatment still embodying the invention and showing the use of recovered oil in the circulation system; and in Figure 5, an elevation partly in section of a treatment still embodying the invention showing the use of recovered oil from the tank in the circulation system.

The invention is well illustrated in a process of treating petroleum oils under substantial pressure and at relatively elevated temperatures with air or other oxygen containing gas, wherein vaporous and gaseous products, and a liquid tar residuum are withdrawn from the treatment zone.

In carrying out such a process, in order to prevent formation or deposition of hard,

coke-like carbon, a positive, controlled, uniform circulation of the oil undergoing treatment is maintained at all times within the body of the oil itself. To thisend, the still 1 is partly filled with oil to a convenient level 2. This oil may be preheated either before entering the still or after it is placed therein by any suitable heating means (not illustrated). Air is forced into the oil through air inlet pipe 8 desirably provided with a series of nozzles 4. In the construction illustrated, the air inlet nozzles are mounted on a ring 5, the latter being connected to air inlet pipe 3 by connecting pipes 6, 6 and 7. Surrounding each air nozzle is a concentric tube 8 through which oil passes, the tubes 8 bein mounted on a ring 9 to which ring, oil is fe through inlet pipe 10. Near the upper oil level, but submerged in the oil is an oil inlet ring 10 connected by pipe 11 to a source of oil supply. This upper oil ring is desirably supplied on its under side 12 with a series of openings through which oil may be projected preferably under pressure into the body of oil in the still 1. The bottom of the still is desirably conical in shape, and near the bottom thereof below the air-oil inlet nozzles, a lower oil inlet pipe 18 is placed desirably provided with a series ofopenings 14: along its side wall, whereby oil may be projected.

into the body of oil in the still, but below the air inlet nozzles. The pipe 13 is fed with oil by pipe 15 connected'with a source of oil sup ply. In the structure illustrated, a common source of oil supply 16, feeds oilto the Y the desired level.

inlet pipes 1O, 11 and 15 through control valves 17,18, 19; the pipes 10, 11 and 15 carrying pressure gages, 20, 21, 22. A vapor outlet 23 is conventionally illustrated, which may be sufficiently large for giving access to the interior of the still. Tar or residuum or 'oil is withdrawn through the tar line 24, located in the bottom of the still 1. Vapors and gases may be withdrawn from the upper part of the still in the usual manner.

In operation, the still is filled with oil to Temperature and pres sure conditions having been adjusted for the purposes in hand, air is forced into the oil through air inlet 3 and oil is injected through oil inlets 10, 11 and 14:. The oil entering through the tubes ornozzles 8 together with the air entering through nozzles i set up an'inner zoneof rising liquid andgas within the central portion of the column of oil. Each air current is thus enveloped in an enclosing sheath of oil. The oil forced through upper ring 10 produces an outer zone of downwardly moving oil. "When gas or vapor reaches the upper portion of the oil, it escapes to the vapor space abovethe oil, while the oil carried to the upper level is returned with the outer downwardly moving oil. Positive circulation is thus set up in the body of oil, the'velocity of circulation being controlled by the rate of feed of air and oil, to the inlet pipes and/or nozzles. Since certain heavier materials tend to segregate in the lower por- 7 like carbon in any substantial amount appears to take place only when the heated oil is allowed to come to rest on a heated surface or in contact with a heated substance, the continuous forced, uniform circulation maintained throughout the body of oil, substan- Eially eliminates the formation of such caron. V

The oil used for producing circulation may be obtained from any desirable sources, and need not be untreated stock alone. In fact, questions of economy require the use of backtrap or returned oil such as oil or condensates from the bubble towers, lighter portions from the tar tank, etc., as subsidiary sources of oil to be mixed with the new or untreated oil.

The following example illustrates a specific application of the invention. The stock treated was fresh parafiin base gas oil. The charging pump was started and oil charged from the supply tank through the preheater. As soon as the latter was full of oil, the pre heater fires were lighted. When the desired oil level in the still was reached, charging was discontinued, and the oil circulated from the still back to the preheater with a surge pump until the temperature of the oil in the still reached 550 F. When the oil temperature in the still reached 525550 F, air was cut into the still, circulation continued and charging of the small amount of fresh charge oil from the oil tank was resumed. When the pressure in the still reached 100 lbs/sq. in., equalizing with the bubble tower was started. As soon as the bottom of the bubble tower reached 450 F. and enough condensate was available in the base of the tower the aforesaid circulation was discontinued, and the backtrap was returned through the preheater, this return of the backtrap through the preheater being continued throughout the remainder of the run. The charging oil and backtrap passing to the still were proportioned between the top and bottom .oil inlets and the combination airoil jets. Proper operating conditions were now maintained. The pressure in the still and bubble tower was 350 lbs/sq. in., the temperature in the still top being approximately 710 F. The air was forced into the still under an average pressure of 443 lbs/sq. in. The oil charged was about 179 bbls. per hour, and air charged was about 835 cu. ft. per minute or 27 95 cu. ft. per bbl. of oil charged. There was obtained about 5.7 bbls. of distillate per hr. The run was continued for about two hundred hours and then arbitrarily discontinued. Inspection of the still and still contents showed that there had been no formation of hard, adherent or coke-like carbon.

The above given description of the apparatus and its operation, and the specific example, should not be taken as limiting. In the illustrated form of the device, but one upper oil inlet ring and but one lower oil inlet pipe is shown. However as many such inlets may be used as are desired, although one of each is generally sufficient to produce the required degree of circulation, in conjunction with the duplex oil-air jets. While these oil-air jets have been shown as concentric tubes or nozzles, separate oil and air bles that would seriously interfere with the circulatory currents set up in the body of oil. This factor is an important one, completely overlooked in the prior art. Besides confining the gas and vapor bubblesto the inner rising column of oil where they assist in enhancing the circulation, the devices described above set up a pronounced circulation in the body of oil, upwardly in the central portion thereof, outwardly at the upper level, and downwardly along the shell and outer portion of the body of oil, and then inwardly again at a zone approximately on a line with the oil-air jets.

This circulatory movement is the preferred one in processes involving heat treatment with concurrent oxygenation and dis,- integration. However if desired, other arrangements of apparatus with consequent variation in the circulatory movements, may be made, it being essential only that in any such arrangement, that suflicient circulation be obtained for the ends sought.

While the apparatus has been diagrammatically illustrated as applied to a vertical still, it may by suitable adjustment be used with a horizontally disposed still. In this case, the oil-air jets may form a series of nozzles projecting from a pipe along the bottom of the still, while the upper oil spray inlet may be disposed as two horizontally placed pipes with downwardly directed spray openings, submerged in the upper portion of the body of oil but parallel with the pipe supplying the oil-air jets. Any tar collecting below the oil-air jets may be flushed along the bottom of the still to one end thereof where it may be removed.

It is desirable to carefully consider the ratio of the incoming fluids and the force exerted by them, in relation to the volume of liquid to be circulated. To obtain the required circulation, either larger volumes of liquid may be circulated, or the differential of pressure may be increased. For example,

a greater volume of oil may be circulated through the still than is actually undergoing treatment therein due to the fact that vapors and gases, and tar are removed either continuously or intermittently. Or the incoming oil may be injected under pressures suffi cient to produce the circulatory movement desired in the body of oil itself. However, in any case, for the best results, the oil level in the still desirably should remain substantially constant. Not only may the several sources of oil for causing circulation, described above, be used, but the backtrap, light tar, fresh stock, etc., may beproportioned between the various oil inlets, as desired. When using oil from the light tar tank, more frequent drags through the tar line, may be made. i j

The oil fed in may be readily used to control or regulate the temperature in the still,

since the incoming oil is cooler than that in The use of cooled oil for keeping the temperature down, particularly when air at increased temperatures isused, is considered to be more advantageous than is the use of internal cooling agents such as steam, when used with the incoming air. The latter expedient may however be employed when desired; The diiferential on the oil charge line need be suflicient only to produce the desired degree of circulation.

For the most efficient circulation, the vertically disposed sprays have proved bestp However, the spray openings and nozzles may be angularlydisposed if desired to give a tangential or whirling movement within the circulating body ofoil, without destroying the circulatory current. Since in such cases much of the force of the injected fluids is consumed in producing such whirling movement thereby diminishing the force available for producing the circulation proper, the vertically disposed sprays and nozzles are considered to be preferable.

It should be particularly noted that in the present case, all stirrers are eliminated, and in fact no elements in motion are required. Further the still is kept practically free from apparatus, the rings and pipes placed therein in accordance with the present invention being reduced to a minimum, and of such simple construction that with the elimination of hard carbon formation, no attention is required by those pipes, etc. within the still.

The stuffing boxes hitherto required in the prior art are avoided with resultant elimination of leaks through such elements-a major source of trouble in prior art devices. I

The present invention maintains the oil or other liquid in circulation, permitting no quiescent zones therein, and no dissemination of wild gas or vapor bubbles throughout the liquid. The circulation is maintained substantially uniform throughout the oil under.- going treatment by supplementing the movement caused by the oil-air jets, at various points in the body of oil removed from the oil-air jets, the secondary circulatory movements complementing that initially induced at the oil-air jets. Sufficient sprays, etc. should be used to obtain the required circulation, and for any given still may be readily present or molten materials wherein uniformity of operating conditions are required. In the treatment of hydrocarbon oils, by the present method, the fluids used for producing circu-c lation are air and oil. But while these are essentially desirable in the indicated process, any fluids may be used depending onvrmaterial undergoingtreatment and the process involved. Even in the indicated process, steam, preferably superheated may be used at some jets, and residual gases such as those obtained from petroleum stills, in general, or in the process itself, may be utilized as part of the injected fluid. V V

The present invention is particularly important in the air blowing of hydrocarbon oils or related materials, particularly under pressure, in view of the fact that hard carbon formation is substantially avoided. Among .the materials that maybe treated there may be mentioned petroleum and its various dis- .tillates, shale products and tars, pitches, waxes, paraffin, sludges, residues from the:

petroleum industry, asphaltic oils, malthas, asphalt, cracked oils and residues from cracking stills, wood tar oils and wood tars, peat distillates, lignite distillates, distillation products from'coal, and oils such as petroleum oil containing solid substances in sus-.

pension, such as coal,'coke, peat, carbon, etc.

lVhile air is primarily used as the oxygen containing gas, oxygen, oxygen-nitrogen mixtures, etcimay be utilized.

The invention is particularly useful in heat treatment processes for petroleum, carriedout under superatmospheric pressure, but may be utilized as well when the treatment is either at or below atmospheric pressures. Substantial pressures of from to 500 lbs/sq. in. with temperatures ranging from 300 to 1000 F. are usable in treating petroleum or other hydrocarbon oils.

Solid bodies or activating substances may be present but. these are not essential, and are generally avoided.

' The still should be of heavy plate sufficient to withstand the pressures that may be de veloped.

The level ofoil undergoing treatment is desirably maintained constant, and the air injected should be substantially deoxygenated during its travel through such column of oil. Deoxygenation depends on a number of factors including the nature of the material undergoing treatment, the depth of such material, the temperature and pressure conditions. V

The products of the process includes fixed gases containing hydrocarbons, condensates both water soluble and water insoluble, from which a wealth of desirable hydrocarbons, oxygen-containing compounds, resins, gums,

gasoline substitutes of anti-knocking characteristics, solvents, etc., etc may be recov' ered,and tarsor residuum such as still bottoms convertible, into, or'useful' for recovery more oil may be withdrawn from the still itself, at any particular point desired and recharged thereto through any of the injecting devices described in ,order to enhance the circulation. If the drags through the tar line are taken at very -frequent intervals or at least at a rate great-erthan the accumulatlon of tar or heavier materials in the bottom of the still, oil may be withdrawn at this point and this oil used for causing circulation in any of the manners described above.

Thus in the diagrammatic showing of Figured, the vapors and gases are taken oil from the still l'vand carried to the bubble tower 2'. In the bubble tower, part of the vapors are condensed to form recovered oil andrelated products, which may then be sent back an-dutilized in the charge oil inlet for producing the circulation in the still.

In Figure 5, the diagrammatic showing includes the utilization of oil recovered from.

the tar tank. For this purpose the material taken 'ofl in the tar line 20. proceeds to the tar tank 21', where the .oil preferably the in the still, but also from the tar or residuum withdrawn therefrom. This fact strikingly diiferentiates the present invention 7 over prior art practice. 7

Having thus set forth my invention, 1 claim:

1. A process of heat treating hydrocarbon oils to produce ligi ter distillates therefrom which comprises maintaining a body of oil under conversion conditions of temperature and pressure, and injecting air and oppositely directednon-planar oil streams thereinto at a sufiicient number of points to produce substantially uniform circulation throughout the body ofoil, of such rate as to substantially eliminate the formation of hard or adherent carbon,

2. A process'of heat treating hydrocarbon oils toproduce lighter distillates therefrom which comprises injecting air and oppositelyvdirected non-planar oil streams within a body of oil under conversion conditions of temperatureand pressure, to produce circu lation Within the body of oil of character and velocity sufiicient to preventformation of hardcarbon,

3. In a process as set forth in claim 2, the steps of obtaining a liquid product from the oil undergoing treatment and injecting that liquid product into the maintained body of oil as a circulation producing stream.

4:. In a process of heat treating a body of petroleum to produce lighter distillates therefrom maintained under conversion conditions of temperature and pressure with air injected thereinto, the step of injecting oppositely directed non-planar oil streams within the body of petroleum to produce circulation therein sufficient to eliminate the formation of hard carbon.

Apparatus for heat treating oils to produce lighter distillates therefrom which comprises a still for maintaining a body of oil at conversion temperatures and pressures, and means for injecting air and oppositely directed non-planar oil streams within said body of oil to produce circulation therein of character and velocity suiiicient to prevent formation of hard carbon.

6. In apparatus as set forth in claim 5, means for obtaining a liquid product from the oil undergoing treatment and means for injecting that liquid product into the maintained body of oil as a circulation producing stream.

7. Apparatus for heat treating oils to produce lighter distillates therefrom which comprises a still for maintaining a body of oil under conversion conditions of temperature and pressure, air and oil inlets near the bottom of said still, for injecting upwardly directed streams of oil and air, an oil inlet in the upper part of the still but below the oil level for injecting circumferentially and downwardly directed'streams of oil, means for receiving tar which settles below the air inlets, means for maintaining said tar in circulation below said air inlets, an outlet conduit for vapors and gases in the upper portion of said still, and means for removing tar from the tar receiving chamber.

8. A process of heat-treating hydrocarbon oils to produce lighter distillates therefrom which comprises maintaining a body of oil under conversion conditions of temperature and pressure, injecting streams of air and 011 within sald body of oil to produce move ment of a substantial portion of said body of oil in a given direction, and injecting a second stream of oil into said body of oil at a point removed from the point of injection of the aforesaid air and oil streams whereby the aforesaid movement of the portion of the body of oil is enhanced, and the deposition of hard carbon is substantially eliminated 9. A process of heat-treating hydrocarbon oils to produce lighter distillates therefrom which comprises maintaining a body of oil under conversion conditionsof temperature and pressure, injecting streams of air and oil within said body of oil to produce controlled movement of a portion of the body of oil for a given distance, and injecting a second stream of oil within said body of oil at the point where such controlled movement of the portion of the body of oil would normally tend to cease, whereby controlled movement of the oil is maintained and the deposition of hard carbon is substantially eliminated.

10. A process of heat treating hydrocarbon oils to produce lighter distillates therefrom which comprises maintaining a body of oil under conversion conditions of temperature and pressure, injecting upwardly directed streams of air within the body of oil in a lower zone thereof, to produce an upwardly moving current of oil and gas and injecting a downwardly directed oil stream into the body of oil in an upper zone thereof to produce a downwardly moving oil current in said body of oil, whereby circulatory currents are set up throughout the body of oil and the deposition of hard carbon is substantially eliminated, allowing residuum to settle below the air inlets but circulating said residuum below said air inlets by injected oil currents. i

11. A process of heat treating hydrocarbon oils to produce lighter distillates therefrom which comprises maintaining a body of oil underconversion conditions of temperature and pressure, injecting upwardly directed streams of air within the body of oilin a lower zone thereof, the incoming air streams being entirely enveloped within injected oil streams,.said injected streams of air producing an upwardly moving current of oil and gas, and injecting a downwardly directed oil stream into the body of oil in an upper zone thereof to produce a downwardly moving oil current in said body of oil, whereby circulatory currents are set up throughout the body of oil and the deposition of hard carbon is substantially eliminated.

12. In a process of heat treating oil under conversion conditions of temperature and pressure with air streams injected thereinto to produce lighter distillates therefrom, the step of entirely enveloping such air streams within streams of injected oil.

13. 'Apparatus for heat treating hydrocarbon oils to produce lighter distillates therefrom which comprises a still for maintaining a body of oil under conversion conditions of temperature and pressure, means for injecting air in upwardly directed streams, into the body of oil near the bottom thereof, means for injecting oil in upwardly directed streams along with the air, and means for injecting downwardly directed oil streams into the body of oil near the upper level thereof, supplementing the upwardly directed streams, whereby circulatory currents are set up in the body of oil.

HENRY C. KIRK. 

